What is the workflow to create animation in Blender?
This depends on your personal workflow and/or the workflow of your contractor/employer. 

Basically (if we wanted to create a simple animation, with just a character) (in my experience) it's always something like this (some of the following tasks are usually - but not always - done by different artists):


Concept phase (Where rough concepts and ideas are gathered and refined - mostly 2D)
Concept models (Very rough models to proof the concepts work in 3D and in general)
Sculpting (Basically "creating" the character in 3D, with all the small details. This results in a highpoly model)
Retopologize (Highpoly models are hard to work with, so you take the model and "rebuild" it, with less polygons. Sometimes - often in games - you have a polycount budget. So your model isn't allowed to have more than x polygons/tris. This results in a lowpoly model)
UV-Unwrapping (In order to "paint" your model (e.g. put a texture on it) you need to unwrap it and create a UV-map. This UV-map is also used for baking)
Baking (You can transfer all the details from your highpoly model to your lowpoly model via a normal map (texture). This normal map and some other maps are generated by "baking")
Texturing (Basically paint your model. This is where the grey chunk gets fancy ;) )
Rigging (In order to animate your model, it need a skeleton. Rigging is basically giving your model a skeleton, which you can animate)
Animation (The skeleton - and with it the model - gets animated)
Lighting (In this stage, lighting is set up. Also arround this time, everything is put together (if that's not done via compositing))
Rendering (Everything is rendered. In small/simple scenes you can put everything in one scene and render it out. However, in more advanced and bigger scenes, the stuff to render is usually split up in several renderlayers, which are then put together in compositing)
Compositing (Like described above, this is where the different parts of the renders are put together. This is also where mat-paintings and VFX are "put in")


I hope this helps you understanding the basic workflow. 
As you can see, 3D and CGI is a very complex topic. 

Greetings